Wattmetric regulator for prime mover dynamo plants



March 24, 1953 Q DUPY 2,632,856

WATTMETRICREGULATOR FOR PRIME MOVER DYNAMO PLANTS Filed, Dec. 10, 1949 3Sheets-Sheet l OL/N L. 0UP),

INVENTOR.

A 7' TOPNEK March 24, 1953 Q DUPY 2,632,856

' WATTMETRIC REGULATOR FOR PRIME MOVER DYNAMO PLANTS Filed Dec. 10, 19493 Sheets-Sheet 2 0L 11v 1.. oupr,

IN VEN TOR.

A TTORNEK March 24, 1953 O L. DUPY 2,632,856

WATTMETRIC REGULATOR FOR PRIME MOVER DYNAMO PLANT-S Filed Dec. 10, 1949s Sheets-Sheet s Q a x I ou/v L. ouPr, 1 & INVENTOR.

A T TORNEK Patented Mar. 24, 1953 UNITED STATES PATENT OFFICE WATTMETRICREGULATOR FOR PRIME MOVER DYNAMO PLANTS Olin L. Dupy, Los Angeles,Calif., assignor of ten per cent to William E. Beatty, Los Angeles,

Calif.

8 Claims. 1

The invention relates to a regulator and more particularly to animprovement in the regulator covered by my U. S. Patent No. 2,248,495issued July 8, 1941.

In the present application as in the patent, use is made of a torquemotor which not only measures the off-normal condition, but alsoconstitutes the means whereby the generator load proportionatelyoperates the regulating element.

In Fig. 8 of the patent, the torque motor is illustrated as a regulatingelement for a threephase alternator. That circuit does not take intoaccount an unbalanced load or the power factor in the line 114, with theresult that the regulator in Fig. 8 of the patent is accurate only forbalanced, noninductive loads.

An object of the present invention is to efiect the regulation of one ormore prime movers driving one or more electric generators viz.alternators in accordance with frequency and/r voltage and adds acorrection in accordance with the actual load, that is, in accordancewith the demanded watts, not the volt-amperes of the load. Any D. C.generators in the combination also add a correction in proportion totheir load.

In the patent, use is made of a spring which tends to open the throttleof an engine driving the alternator while the floating field member isprovided with two windings, one of which aids the spring and the otherof which opposes it.

A further object of the present invention is to provide a regulator ofthe type described wherein the floating field member is provided with asingle winding and a further object is to provide a circuit whichefiects the energy applied to the single winding in accordance with thewatts, not the volt-amperes, in the A. C. circuit of an alternator,and/or according to the watts in the circuit of a D. 0. generator.

For further details of the invention reference may be made to thedrawings wherein- Fig. 1 is a schematic representation of an enginedriven single phase alternator having the regulator of the presentinvention.

Fig. 2 is a schematic representation of an engine driven three-phasealternator having the regulator of this invention.

Fig. 3 is a schematic representation of a plurality of single-phasealternators and a D. C.

generator driven by the same engine and having a the regulator of thisinvention.

Fig. 4 is a schematic representation of a plurality of three-phasealternators driven by the same engine and having the regulator of thisinvention, the dotted line showing of the lower three-phase alternatorand the dotted line connection to the rectifier therebelow representingthe alternator rectifier circuit of Fig. 2.

Referring in detail to the drawings, in Fig. l, as in the patent, theengine I has a throttle 2 and spring 3 tends to open the throttle 2. Therotor 4 is constructed as described in the patent and is driven by theengine I in a clockwise direction through suitable gears indicated at 5.The engine I drives a single phase alternator 6 having a suitable fieldwinding 1 and supplying A. C. to line 8.

In Fig. 1, the floating field member 9 has a single winding ID energizedby direct current by way of the line H which is connected across therectifier 12. In the no load condition, the alternator voltage on line 8is an indication of engine speed. This voltage produces the no loadspeed regulation, by way of transformer l3 and a phase shifting circuitI4, no bucking voltage due to current in line 8 being present in coilll, with no load in line 8. Phase shift circuit I4 is adjusted to alterthe phase of the voltage in the secondary of transformer l8 so that whencurrent fiows in line 8, the voltage induced in the secondary winding llof transformer l5 by the in-phase current in line 8 is in directopposition to the voltage induced in the secondary of winding it so asto reduce the voltage ener gizing rectifier l2 and energizing windingiii of floating field 9, permitting spring 3 to open throttle 2 inaccordance with the true watts of electrical load. A further advantageof the phase shifting circuit 14, is that its impedance changes withfrequency, viz., decreases with increasing frequency. Hence, when thespeed of alternator 6 increases, both the voltage and the frequency inline 3 increase, and each thereof adds its effect in obtaining thedesired regulation. The transformer l5 has a primary winding 16 inseries with the line 8 and a secondary winding [7 in series with thesecondary winding iii of transformer l3 and in series with the rectifierl2.

The phase shifting circuit 14 functions by means of a condenser 26 andresistance 2%, both of which are indicated as being variable althoughafter their proper values have been computed or determined by trial,they may have fixed values.

The proper operation of the floating field 9, so that it will beresponsive to the watts not volt-amperes of the load may be determinedby trial. With no current in the line 8, either the tension of spring 3or the voltage produced by winding [8 is chosen so that position ofthrottle 2 will be such as to produce the proper engine speed at noload. Then a watt meter not shown is inserted in the load circuit, thatis, in line 8 and the resistance 2| and/or condenser 20 are adjusted sothat the floating field 9 operates in proportion to the watts load inline 8, then checked against loads having various power factors. Forincreasing values of in-phase current in line 8 there is producedincreasing values of E. M. F. of the proper phase, in winding II toreduce the voltage produced by winding is by a bucking effect and,hence, in effect, aids the spring 3 in opening the throttle 2 to takecare of the increased load. Any voltage induced in winding I1 due toleading or lagging reactive current flowing in line 8 and through coilI6, will be out phase with the voltage of coil I8 and thereforeineffective in bucking this voltage. The amount of the effect onregulation caused by the load in line 8 is determined by the turn ratioof windings I! and Hi. If, for instance, 10 volts across rectifier I2 isthe value of voltage that holds the throttle in the proper. position forno load engine speed, then with full load in line 8 if it is found thatthe voltage must be reduced to 9 volts in order to open throttle 2 tothe proper position for the desired engine speed, a tap is selected onwinding I! which produces the one volt necessary to oppose the voltageof winding l8 and reduce the voltage to 9 volts.

In Fig. 2, the engine 3% drives a three-phase alternator 3i. As in Fig.1, the spring 32 tends to open the throttle which is operated by afloating field 34 having a single winding 35. Winding 35 is energized bya three-phase rectifier 36 which is energized by a three-phase voltage,which is the alternator voltage and therefore eifects engine speedregulation, and is derived from the voltage of the three-phase line 3?.Con" nected across the line 31 are three transformers 33, as, it havingtheir primary windings star connected across line 3'5 as shown. Theopposing load sensing portion of the regulation is obtained from. thevoltage of transformers H, 42, 43 each having a primary winding inseries with one side of the line 3'! as shown and each having asecondary winding connected to taps id, 45, M respectively, at thesecondary windings of the transformers 38, 35, 40 respectively. Theother terminals of the secondary windings of transformers M to 423 areconnected as indicated at ll, 48, 49 to the rectifier 3b. The endterminals of the secondary windings of transformers 38 to All areconnected in delta as indicated by the connections 58), 5!, 52. In thiscircuit the necessary phase shifting is accomplished by the selection ofproper points to tap onto the windings of coils M, 45, and 16 oftransformers 38, 39 and 4B.

In 2, the current in the output of rectifier 35, that is in the winding34, depends upon the difference of the voltage in transformers 38 to 40and the voltage in transformers 4| to 43, while the tap connections 44to 46 select the proper phase relation to insure that the bucking effectdue to the current in the line 3! is effective only for loads of unitarypower factor.

In Fig. 3, a single phase alternator 558, the same as illustrated inFig. l, and another single phase alternator 6i, and a D. C. generator 52are all driven through a suitable drive indicated at 63, by the engineM. As in the preceding figures, engine 54 is controlled by a throttleiii: urged toward open position by a spring 86, the throttle 65 beingcontrolled by a floating field B! of the torque motor 68. The floatingfield 61 has a single winding 69, the speed sensing portion of theregulating current for the winding 59 being derived from the voltage ofthe alternator 60, as in Fig. 1. The voltage of alternator 60 issupplied through transformer Ill to the rectifier H as described andthis voltage is opposed in proportion to the in-phase voltage from thecurrent transformer 12 as above described. The phase shifter 13 incircuit with the transformer 10 insures that its voltage is effectivelyopposed only by in-phase current in the line M. The rectifier II isconnected in series with a rectifier T5 and with a resistance 76 inseries with the D. C. generator 62. Rectifier 7-5 is energized by a coil11 on the middle leg ii! of a transformer 19, while a second leg 8E3 hasa coil SI connected across the line 82 through a phase shifter 83. Athird leg 84 has a coil 85 in series with the line 32. The phase shifter83 is set or adjusted so that only the inphase current in coil 85 willproduce flux in leg 18 and voltage across rectifier i5. This can bedetermined as above described in connection with Fig. l, by adjustingthe phase shifter 33 so that the floating field ii! operates inproportion to the watts load, The voltage in the output of rectifier 15as well as the voltage across resistance 16 aid the voltage across thesec ondary of transformer 12 in bucking the voltage across the secondaryof transformer 18, to aid the spring 66 in opening throttle 65 inproportion to the load on any one or more of the machines 68, SI and 52.

By way of example, in Fig. 3 the alternators st and BI may be 120 volt,4.00 cycle machines while generator 62 may be the standard D. C. unit of28 volts, 300 amps as used for aircraft.

In Fig. 3 the three leg transformer 19 illustrates an alternativecircuit for obtaining a regulating effect proportional to watts loadonly of alternator 51. Also the A. C. regulating effect derived fromlines 74 and 82 is rectified by the rectifier-s H and 75 into directcurrents, and therefore it is of no consequence that there may be aphase difference between. the alternating currents in lines 14 and 82.

Referring to Fig. 4, the engine 99 through suitable gearing ill drives athree-phase alternator 92 and a three-phase alternator 93, the latterand its regulating circuit to the rectifier 94 being the same as thealternator 3! and its circuit to the rectifier 35 as in Fig. 2. For thealternator 92 in Fig. 4 I have illustrated a different circuit foreffecting regulation only in proper tion to the in-phase load current.For this purpose, across the line 95 is connected a delta arrangement ofreactances indicated at 56, with a tap indicated at 31, 98, 99 foradjusting the connection to the coils Hill, liH, I82 respectively on thethree leg transformers I03, I64 and IE5. Another leg of each transformer33 to N35 has a coil as indicated at I06, I07, I08 in series with oneside of the line 95. Each of the transformers N13 to 35 has a middle leglike Hi9 having a coil thereon like H0, the other similar coils beingindicated at HI and H2. The coils HE to I l 2 are delta connected to thethree-phase rectifier H3. As in Fig. 3, the taps :9! to 89 are adjustedso that only the in-phase current in coils me to I65 will produce fluxin the coils Hi! to H2. Hence, the voltage supplied by coils Hi) to H2to rectifier H3 also depends only on the in-phase current in the line95. Rectifier H3 thus supplies a D. C. voltage in proportion to thevoltage across line 95 altered in proportion to the in-phase current inline 95 and rectifier 94 supplies a D. C. voltage in proportion to thevoltage across line 37 altered in proportion to the iii-phase current inline 3! in Fig. 2. As in Fig. 2, the major portion of the regulationdepends on the voltage of the alternator 3| in Fig. 2, while a loadsensing portion depends on the load on both of the alternators 92, 93.The D. C. voltage across rectifier H3 assists the D. C. voltage acrossrectifier 94 in affecting the torque of the regulator, permitting thespring H4 to open the throttle in accordance with the load on alternator92.

Various modifications may be made in the invention without departingfrom the spirit of the following claims.

I claim:

1. The combination of a prime mover, an alternator driven thereby, aregulator for said prime mover, said regulator comprising a torque motorhaving a rotor and a floating field memher, a winding for said fieldmember, a rectifier for supplying said winding with direct current,means for energizing said rectifier with a voltage of a certain valuedependent on the voltage of said alternator, means for energizing saidrectifier with an opposing voltage of a value dependent on current loadon said alternator, and a phase shifter for relatively shifting thephase of said voltages into opposition only for in-phase load current ofsaid alternator.

2. The combination according to claim 1 wherein said phase shifter hasan impedance which changes with frequency.

3. A regulator comprising a torque motor type of regulator forcontrolling the throttle of an engine driven alternator, said torquemotor having a rotor having a driving connection with said engine and afloating field member having a winding and a spring tending to open saidthrottle, a rectifier in circuit with said winding, a currenttransformer having a winding in series with said alternator, a voltagetransformer having a winding across said alternator and means forenergizing said rectifier from said windings with voltages which are inopposition only for substantially unitary power factor of the load ofsaid alternator, the voltage from said current transformer aiding saidspring.

4. A regulator comprising a torque motor type of regulator according toclaim 3 wherein the voltage from said voltage transformer issubstantially larger than the voltage from said current transformer.

5. A regulator comprising a torque motor type of regulator forcontrolling the throttle of an engine driven alternator, said torquemotor having a rotor having a driving connection with said engine and afloating field member having a winding and a spring tending to open saidthrottle, a rectifier in circuit with said winding, means for energizingsaid rectifier in accordance with the voltage of said alternator, andmeans for reducing the effect of said energizing means and aiding saidspring in accordance with the inphase current load of said alternator.

6. The combination of a prime mover having a throttle, a generatordriven by said prime mover, a regulator for said prime mover, saidregulator comprising a torque motor having a rotor having a drivingconnection with said prime mover and having a floating field memherhaving a winding and a spring tending to open said throttle, a circuitfor supplying to said winding a regulating voltage according to thevoltage of said generator, and a circuit for bucking said regulatingvoltage in accordance with the load of said generator.

7. A regulator comprising a torque motor type of regulator forcontrolling the throttle of an engine driven alternator, said torquemotor having a rotor having a driving connection with said engine and afioating field member having a winding opposing a spring tending to opensaid throttle, a rectifier in circuit with said winding, means forenergizing said rectifier to a major extent in accordance with thevoltage of said alternator, means for correcting the effect of saidenergizing means and aiding said spring to a minor extent in accordancewith the in-phase current load of said alternator, and means forneutralizing the effect of out-of-phase current load of said alternatoron said correcting means.

8. The method of regulating the throttle of an engine driving analternator, said method comprising regulating said throttle to a majorextent in accordance with the voltage of said alternator, correctingsaid voltage regulation to a minor extent in accordance with thein-phase current load of said alternator, and neutralizing the effect ofout-of-phase current load of said alternator on said correction.

OLIN L. DUPY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,533,356 Todd Apr. 14, 19251,586,533 Peterson June 1, 1926 1,675,477 Wilson July 3, 1928 2,015,556Fountain Sept. 24, 1935 2,095,120 Belfils et a1 Oct. 5, 1937 2,248,495Dupy July 8, 1941 2,298,977 Silber et al. Oct. 13, 1942 2,305,952Cravath Dec. 22, 1942 2,472,571 Crary June 7, 1949 2,486,068 Shishini eta1 Oct. 25, 1949

